Statistical investigation of the noise added to a model of the effect of solar activities on the plasma of the ionosphere using DEMETER satellite data

Although a relation between ionospheric anomalies and occurrence of strong earthquake has been studied for several decades, the issue of finding anomalies in ionospheric parameter before earthquakes has been always a matter of controversy among scientific community. In this way, the study of the ionosphere by satellite observers plays a significant role in assessing the feasibility of finding anomalies in ionospheric parameters as short-term precursors of earthquakes. Regardless of whether this assertion about ionospheric precursor is true or false, the ionosphere has been shown to be affected more by solar activities than other events such as seismic activities; thus, the modeling of ionospheric variation caused by solar activities is valuable in assessing the possibility of ionospheric precursors. One of the most famous satellites launched to investigate the ionospheric plasma perturbation associated with solar and seismic activities is the DEMETER, the French micro-satellite. To carry on such investigation, one of its payloads, the onboard IAP experiment, allows for the measurement of important plasma parameters including ion composition densities and their temperature. The current work presents a statistical distribution for the noise added to the proposed model describing the regular effect of solar activities on the ionospheric plasma above Iran during one half-orbit time of the DEMETER (~35 min) in the absence of an earthquake and a quiet time condition. The results of this study show that the proposed modeling noise statistically agrees with the Gaussian distribution; however, its variance may vary from one day to another. In other words, the noise is a non-stationary random process. The proposed model is then evaluated by a set of experimental data. The results of this evaluation show that the measured data follow the proposed model.